<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <input type="text" name="" id="i_row" placeholder="输入行" />
    <input type="text" name="" id="i_col" placeholder="输入列" />
    <button id="calc">打印</button>
    <script>
      var rows = document.getElementById("i_row");
      var cols = document.getElementById("i_col");
      calc.onclick = function () {
        var m = parseInt(rows.value);
        var n = parseInt(cols.value);
        for (var i = 1; i <= m; i++) {
          for (var j = 1; j <= n; j++) {
            document.write("*");
          }
          document.write("<br>");
        }
      };
    </script>
  </body>
</html>
